A new book, “Trust Your Gut,” explores the relationship between human health and the trillions of microbial cells that live in the gut, as well as the stresses in life that can disrupt those cells and cause serious health problems.

If the book sounds complex, don’t worry, said Dr. Greg Plotnikoff, a co-author.

“It’s easily digestible.”

Humor aside, the book explores an emerging frontier of medicine and gastrointestinal diseases such as irritable bowel syndrome, said Plotnikoff, an integrative medicine specialist for Allina Health in Minneapolis.

People are surprised to learn how much influence the bacterial cells that live in their digestive systems have on health. New studies have shown they also influence weight gain and loss.

“ ‘What, our gut bacteria regulates our mood, our energy, our immune function and our metabolism?’ ” said Plotnikoff, characterizing how people react. “‘Wait a second, I thought I was in control!’ But our bacteria actually might control us in important ways.”

Plotnikoff said there are millions of Americans with painful digestive problems who aren’t helped by traditional medicine. The book, co-authored by local health psychologist Mark Weisberg, seeks to give them hope by telling the stories of Minnesotans who made lifestyle changes and overcame their digestive problems.

“This grin-and-bear-it approach to life is not satisfactory,” Plotnikoff said. “People have gone from hopeless to kind of exuberant, from depleted to vital, from defined by an illness to not defined by an illness.”

A good diet is key. Cultured foods such as yogurt and cottage cheese support a healthy “mind-gut connection,” Plotnikoff said, as do fermented foods such as sauerkraut and vegetables such as leeks and artichokes.

But diet is only one component. Outside stresses can be toxic to the ecosystem that lives in the gut.

“Our outer ecology directs our inner ecology,” he said. “You could be the Dalai Lama, but if you live on top of a firehouse, your body is going to experience physiological stress and you’re going to experience stress.”

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